CN219754880U - Wind wheel and contain its axial fan - Google Patents

Abstract

The utility model discloses a wind wheel and an axial flow fan comprising the same, wherein the wind wheel comprises a hub, a closed outer ring and a plurality of blades; the root parts of the blades are arranged on the outer circumference of the hub, and the top parts of the blades are arranged on the inner wall of the closed outer ring; the two sides of the fan blade connected with the root and the top of the fan blade respectively form a front edge and a rear edge, and the air quantity flows from the front edge to the rear edge; the fan blades are asymmetrically distributed in the circumferential direction, the central shaft of the hub is used as the center of a circle, the front ends of the blade tops of two adjacent fan blades are arc-shaped endpoints to form a fan-shaped area, and the central angles of the two adjacent fan-shaped areas are different; the rear edge is provided with saw teeth with gradually increased tooth width along the radial direction. The utility model improves the ventilation quantity and reduces the working noise on the premise of not increasing the size of the fan.

Description

Wind wheel and contain its axial fan

Technical Field

The present utility model relates to axial fans, and particularly to a wind wheel and an axial fan including the same.

Background

The axial flow fan is used as an important radiating device of the energy storage device, the ventilation quantity of the axial flow fan influences the performance and the service life of the energy storage device, and the noise influences the working environment of people. The axial flow fan mainly comprises a wind wheel, a base and a motor. When the wind wheel rotates, air axially enters the wind wheel from the air inlet, and is pushed by blades on the wind wheel to raise the energy of the air, so that the kinetic energy of the air is converted into pressure energy, and the heat on the energy storage equipment is taken away. In order to improve the performance and lifetime of energy storage products, high performance (high efficiency, large air volume and high pressure) fans are required, but high performance fans also increase more aerodynamic noise.

As the demand of the energy storage device for the heat dissipation system is continuously increased, the static pressure is increased, and meanwhile, the ventilation quantity is required to be increased, and the noise is increased due to the increase of the ventilation quantity. Although the air volume and noise can be increased and decreased by increasing the size and decreasing the rotation speed, the method is limited by the installation space of the user and has a certain limitation. Therefore, the fan cannot meet the customer requirements of large air volume and low noise.

At present, most of axial flow fan wind wheels are designed with open blade tops, when the ventilation volume is large, the pressure difference between the working surface and the back surface of the blades is increased, backflow is easy to occur at the blade tops, ventilation efficiency is affected, turbulence phenomenon is easy to occur if the outer rings are directly adopted to be sealed at the blade tops, vibration noise is caused, although the prior art discloses a mode of adopting unevenly distributed blades or increasing saw teeth to reduce noise, the saw teeth are designed to divide and scatter strong concentrated vortex into a plurality of small vortices, and therefore boundary laminar flow intensity is reduced, and the conventional design adopts a uniform saw tooth width design, vortex is not divided according to the surface flow condition of the blades, broadband noise cannot be improved, ventilation efficiency is also reduced, the influence is particularly obvious, and low noise requirements cannot be met yet.

Therefore, how to design a large-air-volume axial flow fan capable of reducing fan noise without increasing the size of a wind wheel and reducing ventilation quantity is a technical problem to be solved at present.

Disclosure of Invention

In order to solve the technical problems that the fan noise is reduced and the ventilation quantity is reduced easily, and the requirements of large air quantity and low noise cannot be met in the axial flow fan in the prior art, the utility model provides a wind wheel and the axial flow fan comprising the wind wheel.

The utility model provides a wind wheel, which comprises a wheel hub, a closed outer ring and a plurality of fan blades; the root parts of the blades are arranged on the outer circumference of the hub, and the top parts of the blades are arranged on the inner wall of the closed outer ring; the two sides of the fan blade connected with the root and the top of the fan blade respectively form a front edge and a rear edge, and the air quantity flows from the front edge to the rear edge; the fan blades are asymmetrically distributed in the circumferential direction, the central shaft of the hub is used as the center of a circle, the front ends of the blade tops of two adjacent fan blades are arc-shaped endpoints to form a fan-shaped area, and the central angles of the two adjacent fan-shaped areas are different; the rear edge is provided with saw teeth with gradually increased tooth width along the radial direction.

Further, the central angles of two adjacent fan-shaped areas are 49-59 degrees.

Further, the tooth width of the saw teeth is 5 mm-11 mm.

Further, the front edge comprises a main air inlet edge and a forward sweep connected with the top end of the main air inlet edge, and the forward sweep extends in a direction away from the rear edge.

Further, the sweepforward and the main air inlet side are in transition through a round angle.

Further, the size of the transition fillet radius R of the sweepforward and the main air inlet side is 14-18 mm.

Further, the size of the transition fillet radius R of the sweepforward and main air inlet side is 16mm.

Further, the central angle D formed by the top end of the main air inlet side and the forward-swept top end is 8-12 degrees.

Further, the central angle D formed by the top end of the main air inlet side and the forward-swept top end is 10 degrees.

The utility model also provides an axial flow fan which comprises the wind wheel.

The beneficial effects of the utility model are as follows:

the wind wheel and the axial flow fan comprising the same, disclosed by the utility model, have the advantages that the top ends of the blades are sealed by utilizing the sealing outer ring, the backflow of the blade tops is avoided, ventilation noise is reduced by the asymmetric design of the blades and the way of adding saw teeth on the rear edge, and meanwhile, the tooth pitch of the saw teeth is gradually increased along the radial direction, so that the noise problem is solved from a plurality of aspects of reducing broadband noise, noise peaks and the like, and on the premise of ensuring the ventilation efficiency, the ventilation quantity is improved, and the working noise is reduced.

Drawings

The utility model will be further described with reference to the drawings and examples.

FIG. 1 is a front perspective view of a particular embodiment of a wind turbine according to the present utility model;

FIG. 2 is a rear perspective view of an embodiment of a wind turbine according to the present utility model;

FIG. 3 is a front view of FIG. 1;

FIG. 4 is an enlarged view of a fan area of a first fan blade according to the present utility model;

fig. 5 is an enlarged schematic view of the upper half of fig. 3.

In the figure, 1, a hub, 2, a closed outer ring, 3, fan blades, 301, a front edge, 3011, a forward sweep, 3012, a main air inlet edge, 302, a rear edge, 4, a working surface, 5, a back surface, 6, a first fan blade, 7, a second fan blade, 8, a seventh fan blade, 9, a fan-shaped area, 10 and saw teeth.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

Example 1

As shown in fig. 1-4, a wind wheel comprises a hub 1, a closed outer ring 2 and a plurality of blades 3; the root parts of the blades 3 are arranged on the outer circumference of the hub 1, and the top parts of the blades 3 are arranged on the inner wall of the closed outer ring 2; the two sides of the fan blade 3 connecting the root and the top of the fan blade 3 respectively form a front edge 301 and a rear edge 302, and the air quantity flows from the front edge 301 to the rear edge 302. When the air quantity is increased, the pressure difference between the working face 4 and the back face 5 of the fan blade 3 is increased, wherein the closed outer ring 2 is a circular ring with no opening on the circumferential surface, the design of the closed outer ring 2 can block the air quantity at the top of the fan blade 3, and the air flow is prevented from flowing back to the back face 5 from the working face 4 of the fan blade 3 through the top of the fan blade 3, so that the ventilation efficiency is reduced. The fan blades 3 are typically twisted blades.

When the axial flow fan works, the air quantity flows in from the front edge 301 of the fan blade 3 and then flows out from the rear edge 302 of the fan blade 3, and the wind wheel can generate discrete noise in the rotating process, and the noise directly influences the sound quality of the axial flow fan and the experience of customers. Therefore, the fan blades 3 of the present utility model are asymmetrically distributed in the circumferential direction, the center axis of the hub 1 is used as the center of a circle, the front ends of the blade tops of two adjacent fan blades 3 are arc-shaped endpoints to form a fan-shaped area 9, the blade tops are the tops of the fan blades 3, the front ends are the ends of the blade tops connected with the front edge 301, and are the ends contacting the air flow first, and the central angles of the two adjacent fan-shaped areas 9 are different, so that the rotation frequency of the fan can be reduced, and the noise of the fan is reduced.

When the fan works, the blades periodically act on air particles, or the moving gas and the machine body are periodically disturbed, so that the gas pressure pulsation is caused to generate noise; after the blades are unevenly distributed on the periphery of the hub 1 and the blades are unevenly distributed at intervals, the periodic rule of the blades is broken, the frequency of the blades is reduced, the frequency rule of fundamental waves and harmonic waves is broken, the peak value of fan noise is effectively reduced, and the noise of the fan is reduced as a whole.

Meanwhile, the trailing edge 302 is provided with saw teeth 10 with tooth widths gradually increasing in the radial direction. Blade trailing edge vortex shedding and wake are one of the important factors affecting axial fan noise and flow losses, and trailing edge 302 modification may affect trailing edge vortex and wake flow. The serrations 10 on the trailing edge 302 divide the strong concentrated vortex into small vortices, thereby reducing boundary layer flow strength and improving boundary layer flow conditions, thereby reducing wake vortices. The size of the broadband noise is mainly determined by the fluid condition of the turbulent boundary layer of the blades, the speed of the airflow is gradually increased from the hub 1 to the closed outer ring 2, the tooth width of the saw teeth 10 is gradually increased from the hub 1 to the rim, the cross-sectional area of the small vortex is gradually increased from the hub 1 to the closed outer ring 2 in a plurality of small vortices after being divided, and the larger the cross-sectional area is, the smaller the speed is, so that the change of the airflow velocity in the radial direction of the trailing edge 302 can be reduced, namely, the wake flow separation is reduced, and the broadband noise is reduced.

In summary, the present utility model reduces noise of the axial flow fan by the asymmetric blade distribution and the design of adding the saw teeth 10 to the trailing edge 302, reduces broadband noise by the design of increasing the tooth width of the saw teeth 10 in the radial direction, reduces noise, and avoids flow loss by the design of the closed outer ring 2, and even under the condition of larger ventilation volume, noise can be controlled within a smaller value, thereby realizing a large-air-volume ventilation effect with high ventilation efficiency and small noise.

Preferably, the central angles of two adjacent fan-shaped areas 9 are 49-59 degrees, as shown in fig. 3, the number of the fan-shaped areas 9 is seven, the area surrounded by the connection between the top of the adjacent fan-shaped areas 3 and the front edge 301 is the fan-shaped area 9, the seven fan-shaped areas 3 are named as the first fan-shaped area 6, the second fan-shaped area 7, … … and the seventh fan-shaped area 8 on the circumference in sequence, the connection line between the top of the first fan-shaped area 6 and the center of the circle and the connection line between the top of the second fan-shaped area 7 and the center of the circle form a fan-shaped area 9, the first fan-shaped area 6 is positioned in the fan-shaped area 9, the central angle of the second fan-shaped area 7 is the central angle of the second fan-shaped area 7. The central angles of the seven fan blades 3 are preferably increased in sequence, so that dynamic balance is ensured, and vibration and noise of the fan are reduced. The central angle a1 of the first fan blade 6 is 49 degrees, and the central angle a7 of the seventh fan blade 8 is 59 degrees.

Too large a tooth width cannot improve wake vortex shedding and wake phenomena, too small a tooth width increases wake flow separation and increases broadband noise, and therefore, as shown in fig. 4, the tooth width L of the saw tooth 10 is preferably 5mm to 11mm. The tooth width of the teeth 10 closest to the hub 1 is 5mm and the tooth width of the teeth 10 closest to the closure outer ring 2 is 11mm.

Example two

On the basis of the first embodiment, the leading edge 301 comprises a main air intake side 3012 and a forward sweep 3011 connected to the top end of the main air intake side 3012, the forward sweep 3011 extending away from the trailing edge 302. Forward sweep 3011 enables adjustment of the shock structure within the fan to improve fan performance by reducing shock strength and shock losses. The change in the vane leading edge 301 curve from the main inlet side 3012 to the forward sweep 3011 essentially re-establishes radial balance of the vane flow, thereby affecting the flow characteristics of the air flow in the channel. The airflow contacts the forward skimming 3011 of the blade top at first, so that supercharging work is performed on the airflow, the pressure of the airflow at the blade top is improved, the top pressure of the blade is higher than the root pressure (namely, the blade top pressure is higher than the blade root pressure), and the accumulation of the surface layer of the blade top area is favorably improved, so that the blade top vortex generated by the airflow on the blade 3 is reduced, and the noise and the power consumption of the fan are reduced.

Preferably, the forward sweep 3011 and the main air inlet edge 3012 are in rounded transition, so that flow loss caused by abrupt change of flow velocity is avoided. As shown in FIG. 5, the transition fillet radius R of the forward sweep 3011 and the main intake side 3012 is preferably 14mm to 18mm. R=16 mm in this example.

In further design, the central angle D formed by the top end of the main air inlet side 3012 and the top end of the forward sweep 3011 is 8-12 degrees. The central angle D is an included angle between a connecting line of the top end of the main air inlet side 3012 and the center of the wind wheel and a connecting line of the top end of the forward sweep 3011 and the center of the wind wheel. Too large a central angle D can interfere with the previous fan blade 3, and too small a central angle D can reduce the improvement effect of the blade top vortex. In this embodiment, the central angle D formed by the top end of the main air inlet 3012 and the top end of the forward sweep 3011 is 10 °.

Example III

An axial fan comprises the wind wheel. The axial flow fan can solve the problems of performance and noise of the axial flow fan with the static pressure of more than 350Pa and meet the requirements of large air quantity and low noise.

In the description of the present utility model, it should be understood that the terms "axial," "radial," "circumferential," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model.

Furthermore, in the description of the utility model, unless otherwise indicated, the meaning of "a number" is two or more.

In this specification, a schematic representation of the terms does not necessarily refer to the same embodiment. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments.

With the above-described preferred embodiments according to the present utility model as an illustration, the above-described descriptions can be used by persons skilled in the relevant art to make various changes and modifications without departing from the scope of the technical idea of the present utility model. The technical scope of the present utility model is not limited to the description, but must be determined according to the scope of claims.

Claims (10)

1. A wind wheel, characterized in that: comprises a hub (1), a closed outer ring (2) and a plurality of fan blades (3); the root of the fan blade (3) is arranged on the outer circumference of the hub (1), and the top of the fan blade (3) is arranged on the inner wall of the closed outer ring (2); the two sides of the fan blade (3) connected with the root and the top of the fan blade (3) respectively form a front edge (301) and a rear edge (302), and the air quantity flows from the front edge (301) to the rear edge (302);

the fan blades (3) are asymmetrically distributed in the circumferential direction, the central shaft of the hub (1) is used as the center of a circle, the front ends of the blade tops of two adjacent fan blades (3) are arc-shaped endpoints to form a fan-shaped area (9), and the central angles of the two adjacent fan-shaped areas (9) are different; the trailing edge (302) is provided with saw teeth (10) with gradually increased tooth widths along the radial direction.

2. A wind rotor according to claim 1, wherein: the central angles of two adjacent fan-shaped areas (9) are 49-59 degrees.

3. A wind rotor according to claim 1, wherein: the tooth width of the saw teeth (10) is 5 mm-11 mm.

4. A wind rotor according to claim 1, wherein: the leading edge (301) comprises a main air inlet side (3012) and a forward sweep (3011) connected to the top end of the main air inlet side (3012), the forward sweep (3011) extending in a direction away from the trailing edge (302).

5. A wind rotor according to claim 4, wherein: the sweepforward (3011) and the main air inlet side (3012) are in transition through a round angle.

6. A wind rotor according to claim 5, wherein: the size of the transition fillet radius R of the sweepforward (3011) and the main air inlet side (3012) is 14-18 mm.

7. A wind rotor according to claim 6, wherein: the size of the transition fillet radius R of the sweepforward (3011) and the main air inlet side (3012) is 16mm.

8. A wind rotor according to claim 5, wherein: the central angle D formed by the top end of the main air inlet side (3012) and the top end of the forward sweep (3011) is 8-12 degrees.

9. A wind rotor according to claim 8, wherein: the central angle D formed by the top end of the main air inlet side (3012) and the top end of the forward sweep (3011) is 10 degrees.

10. An axial fan, characterized in that: a wind turbine comprising any of claims 1-9.